1. Field of the invention.
The present invention relates to the use of coherent energy pulses, as from high power pulsed lasers, in the laser peening or shock processing of solid materials, and, more particularly, to an apparatus for containing the laser peening operation. A processing cell for laser peening is thus constructed that acts as a laser peening workstation.
2. Description of the related art.
Known methods for shock processing of solid materials, particularly laser shock processing solid materials, typically use coherent energy as from a laser beam oriented perpendicular to a workpiece.
Laser shock processing techniques and equipment can be found in the U.S. Pat. No. 5,131,957 to Epstein using transparent overlay materials and opaque overlay materials on a workpiece.
It has been found through experience with laser shock processing systems, that problems occur as the process speed is increased. Of particular importance is that of protecting the optics of the laser peening system, particularly those of the lenses and mirrors, from the effects of the laser peening process itself. Such problem effects include the high velocity ejection of transparent overlay material, opaque overlay material, vaporized particles, and other debris from the laser peening area on the workpiece. Other operational problems become evident, such as debris from previous laser peening operations remaining airborne or within the laser beam path of a subsequent laser peening operation. Such subsequent laser peening operation is thereby degraded because of such debris within the beam path. Additional effects of increased exposure to the by-products of the laser peening process on operators and observers is noted as process speed increases.
A prior system to increase the protection of the laser peening, system optics was to move such optics away from the laser peening area, thus using distance to solve the problem. This necessitates creating optics with a long focal length so that there is sufficient distance between the laser peening operation and the optics in the laser peening system.
What is needed in the art is a compact apparatus to reduce floor space requirements of the laser peening system, protect the laser beam delivery optics, and ensure a cleaner laser beam path to the workpiece.